International Publication WO 98/19097 published May 7, 1998 and filed Oct. 17, 1997 by applicant STUCCHI S. R. L. discloses a male half of the coupling in FIG. 1 thereof which includes a seal 40 carried in a fixed body 32, a piston 37, a safety valve 37 abutting an inner element 34, and, a relief valve 46 being a ball valve 46 actuated by pin 45 for venting to chamber 48. U.S. Pat. No. 5,592,970 to Stucchi et al. issued Jan. 14, 1997 discloses structure similar to WO 98/19097 except the relief valve and pin are missing. The '970 patent is directed to preventing the blowout of seal 40 by covering it with bush 10.
The structure disclosed in WO 98/19097 will leak by the ball valve 46 and the interface between valve 73 and inner body member 34 at low pressures, for example, below 500 psig. Leaking around valve 46 and the interface negates the purpose of the relief valve 46 as the volume available will be filled. Leakage may occur at pressures greater than 500 psig but the increased pressures tend to enhance the metal to metal seals employed by STUCCHI S. R. L. in WO 98/19097.
U.S. Pat. No. 3,498,324 to Breuning discloses secondary valves which first engage each other and open causing a flow through the secondary flow passages from the high pressure side to the low pressure side of the coupling.
The instant invention provides a relief valve which seats on a seal in the female half of the coupling. A high capacity passageway is supplied through the main valve of the female half of the coupling. The relief valve of the instant invention is actuated by a first actuator and a second actuator (push pin) having flat sides. Ports are supplied in the main valve to provide increased venting capacity. The first actuator is driven toward the second actuator (push pin) by a sliding sleeve valve under the urging of the male half of the coupling.